Electroless plating is a metal deposition technique widely used in the coating industry. It is the method of choice to plate substrates with complex geometries and nonconductive surfaces, such as polymers and ceramics, since it is based on a chemical reduction in solution rather than on an external electrical energy source like the electroplating method. Among others, examples of well-established applications are the electroless deposition of decorative metal coatings such as gold and silver, wear and corrosion resistant nickel coatings, particularly to coat drive shafts, rotors, and bathroom fixtures, as well as the electroless deposition of copper in electronic devices as diffusion barriers and conductive circuit elements. In the academic research, electroless plating is extensively used thanks to its low cost, simple equipment and versatility that allow rapid prototyping. Two common applications are the coating of small particles and the selective plating of flat surfaces. Metal coated ceramic particles are of enormous interest in many scientific fields, e.g. fluorescent diagnostics in biochemistry, catalysis, and fabrication of photonic crystals. Metal coated ceramic nanoparticles and microparticles are also gaining attention as potential candidates in the fabrication of higher quality metal matrix Composites, which is one of the applications addressed by this work. Metal coated ceramic particles are easier to integrate in metal matrix composites, avoiding aggregation caused by the low wettability of the particles by the matrix metal, and are potentially shielded from oxidation and undesired chemical reactions that take place at the interface between the particles and the metal Matrix. Electroless plating is an autocatalytic process, meaning that the deposited metal atoms catalyze the deposition of further metal. In order to achieve the first stable metal seeds on a surface, the latter has to be functionalized. Without this functionalization the metal ions in the electroless plating bath are not reduced or are simply reduced to metal nanoparticles in solution. The traditional activation step for nonconductive surfaces is performed by immersion of the substrate in palladium based solutions, which is very time-consuming and extremely expensive. In particular for nanoparticles, previous work showed that at least 1015 Pd atoms/cm2 are required for a uniform activation of a surface, meaning that in the case of nanoparticles with a surface area of about 100 m2/g are necessary 6.4 g of palladium for each gram of substrate. Assuming a price of about 150 €/g (laboratory scale) for palladium nanoparticles and palladium precursors used for surface activation, it results that the activation of 1 g of nanoparticles costs around 1000 €. Such costs are suboptimal considering the typical production scale, and therefore alternative functionalization methods are desired. In this work, new organic-based functionalization methods based on (3-mercaptopropyl)triethoxysilane to functionalize oxide particles, 3-aminopropylphosphonic acid to activate carbide particles and a substrate-independent method based on the bioinspired polydopamine are developed and investigated in detail, together with the respective electroless plating baths, which often have to be specifically tailored regarding the different reactivity of the different molecules and substrates. Furthermore, in the fabrication of metallic patterns on substrates by electroless plating, new, simple, and cost-effective activation and metal deposition processes are desired. In this work, two new methods are presented, one based on the printing of (3-mercaptopropyl)triethoxysilane by microcontact printing, the other based on the capillary force lithography of polymethylmethacrylate.

Aufgrund von guten Eigenschaften als Kupferdiffusionsbarriere und guter elektrischer Leitfähigkeit könnte sich Ruthenium und Ruthenium basierte Legierungen als Kupferdiffusionsbarriere eignen. Auf eine theoretische Aufarbeitung von Elektromigrationsmechanismen und in der Praxis eingesetzte Elektromigrationsteststrukturen folgen beschleunigte elektrische Elektromigrationstestergebnisse. Es konnte gezeigt werden, dass das System Kupfer, Ruthenium, Tantalnitrid Elektromigrationsstabiler als das konventionelle System Kupfer, Tantal, Tantalnitrid ist.:1 Einleitung 1 2 Stand der Forschung 2 2.1 Migrationsarten 2 2.2 Praktische Formulierung des Mechanismus der Elektromigration 2 2.3 Transportpfade der Elektromigration 3 2.4 Einflüsse auf die Elektromigration 4 2.4.1 Übersicht 4 2.4.2 Quereinfluss des mechanischen Stresses (Blech-Effekt) 5 2.4.3 Quereinfluss durch thermisch induziertem Stress 6 2.4.4 Materialwanderung aufgrund eines Temperaturgradienten 8 2.4.5 Einfluss des Leiterbahnmaterials (Legierung) 8 2.4.6 Einflüsse der Mikrostruktur 8 2.4.7 Einflüsse der Passivierung der Leiterbahnen 9 3 Theoretische Untersuchungen 9 3.1 Untersuchte Elektromigrationsteststrukturen 9 3.1.1 NIST-Struktur 9 3.1.2 Untersuchungen mithilfe der NIST-Struktur 10 3.1.3 Schlitz-Struktur 11 3.1.4 Bestimmung des Flächenwiderstandes RF = r=A der Schlitz-Struktur 12 3.1.5 Schlitzlängenänderungsgeschwindigkeit der Schlitz-Struktur 13 3.1.6 Prinzipielles Vorgehen zur Bestimmung der Schlitzlängenänderungsgeschwindigkeit als Kriterium für Elektromigrationsbeständigkeit 14 3.1.7 Blech-Struktur 15 3.1.8 Untersuchungen mithilfe der Blechstruktur 16 3.2 Vergleich der untersuchten Elektromigrationsteststrukturen 16 4 Experimentelle Untersuchungen 17 4.1 Beschreibung des Versuchsaufbaus 17 4.2 Evaluation der Messvorraussetzungen 18 4.2.1 Temperaturbeständigkeit der Messanordnungen 18 4.2.2 Oxidationsbeständigkeit der Schlitz- & Blechstruktur 19 4.2.3 Vernachlässigung Kupfer- und Leitungswiderstände 21 II 4.2.4 Untersuchungen bei verschiedenen Stromdichten (Schlitzstruktur) 22 4.2.5 Evaluation der günstigsten Schlitzlänge für Klassifikationstests 24 4.3 Untersuchungen an der NIST-Struktur 26 4.3.1 Ergebnisse 26 4.3.2 Probleme beim Versuchsaufbau und mögliche Lösungen 27 4.4 Untersuchungen an der Schlitz-Struktur 28 4.4.1 Bestimmung des Flächenwiderstands RF 28 4.4.2 Bestimmung der Schlitzlängenänderungsgeschwindigkeit 28 4.4.3 Optische Probenauswertung mittels TEM und FIB-Schnitt 30 4.4.4 Vergleich von Ta mit Ru und Ru0;95Mn0;05 31 4.4.5 Probleme beim Messaufbau und mögliche Lösungen 31 4.5 Untersuchungen an der Blechstruktur 33 4.5.1 Untersuchungen bei verschiedenen Stromdichten 33 4.5.2 Untersuchung bei verschiedenen Temperaturen 35 4.5.3 Probleme bei den Messungen und mögliche Lösungen 36 5 Zusammenfassung 37 6 Literaturverzeichnis 38

Den Kern der Untersuchungen bildete die Messung der mechanischen Spannungen in dünnen Kupferschichten während thermischer Zyklen und nach Belastung durch Vierpunktbiegung. Parallel dazu wurden Charakterisierungen der Korngröße, der Textur und korninnerer Defekte, inbesondere von Versetzungen durchgeführt. Bei den Spannungsmessungen fielen folgende Besonderheiten auf: (i) höhere Festigkeiten mit abnehmender Schichtdicke, (ii) hohe Verfestigungsraten bei der Abkühlung, (iii) Asymmetrie der Fließspannungen in Zug- und Druckrichtung und (iv) hohe Spannungen bei hohen Temperaturen. Da die klassischen Plastizitätsmodelle diese Besonderheiten zu erklären vermögen, wurden zwei neue Modelle entwickelt. Das erste beschreibt eine effektive Verfestigung auf der Basis elastischer Wechselwirkungen zwischen mobilen Versetzungen und sich an der Schicht/Substrat-Grenzfläche ansammelnder Versetzungen. Das zweite Modell bezieht sich auf das Korngrenzendiffusionskriechen und erklärt dessen Behinderung durch die unvollständige laterale elastische Relaxation auf einem Substrat haftender Körner. Das gesamte thermomechanische Verhalten kann nur aus dem Zusammenwirken verschiedener strukturbildender und Plastizitäts-Mechanismen beschrieben werden.

Das PICTS-Verfahren ist eine der am häufigsten eingesetzten Methoden zur Charakterisierung semiisolierender Halbleiter. Die methodischen Fortschritte bei der Ermittlung von Störstellenparametern mit diesem Verfahren werden in dieser Arbeit vorgestellt. Als praktikable Methode für den Nachweis einer temperaturabhängigen Änderung des Besetzungsverhältnisses einer Haftstelle wird die Normierung auf die Emissionsrate der Elektronen eingeführt. Es wird gezeigt, dass Peaks, bei denen diese Normierung misslingt, nicht für die Ermittlung der Störstellenparameter herangezogen werden dürfen. Die Untersuchungen belegen, dass für die vollständige Umladung der Störstellen eine geeignete Anregungsintensität verwendet werden muss. Durch PICTS-Messungen an Kupfer-dotierten Proben wird eine systematische Abhängigkeit der Peakhöhen Kupfer-korrelierter Peaks vom Kupfergehalt der Proben nachgewiesen. Mit den Untersuchungen wird belegt, dass sich Kupfer mittels PICTS bis zu einer minimalen AES-Kupfer-Konzentration von [Cu]min ca. 5·1E14/cm^3 nachweisen lässt.

This study investigated several somatostatin analogues labeled with copper-64 for imaging and targeted therapy of SSTr positive cancer. Among three new cross-bridged bifunctional chelators coupled to Y3-TATE, 64Cu-CB-TE2A-Y3-TATE had the most favorable tumor targeting properties. The introduction of ionizable linker groups could not remedy the slow clearance from the kidney, and other modifications will be necessary to resolve this issue. The emerging idea of using the copper-64-labeled somatostatin antagonist 64Cu-CB-TE2A-sst2-ANT as a tumor targeting agent will require further experimentation. This radiopharmaceutical showed promising initial results in a biodistribution study in male Lewis rats, however, it should be compared to 111In-DOTA-sst2-ANT in the same model. Nuclear localization of copper-64 from two somatostatin analogues differing in their chelate stability strengthened the hypothesis of copper-64 dissociation from the bifunctional chelator prior to trafficking to the nucleus. However, the increased nuclear uptake of copper-64 from the less stable 64Cu-TETA-Y3-TATE did not result in a significant effect on cell killing of A427-7 cells. In experiments with [64Cu]copper acetate and the EGFR-antibody 64Cu-DOTA-cetuximab, the tumor suppressor protein p53 was identified as a mediator of the nuclear transport of copper. 64Cu-DOTA-cetuximab was also utilized in five cervical cancer cell lines with a wide range of EGFR expression. EGFR quantification by saturation receptor binding, and EGFR function as determined via internalization of 64Cu-DOTA-cetuximab closely followed the expression pattern of these cell lines found via EGFR mRNA profiling. This constitutes a first step in the evaluation of cetuximab for the treatment, and of 64Cu-DOTA-cetuximab for the imaging of advanced cervical cancer, as EGFR expression on the tumor cell surface clearly can be quantified and visualized with this experimental system. Copper-64 has been used in this study to probe the basic biochemical process of intracellular copper trafficking, and for the targeting of cell surface receptors via radiolabeled peptides and antibodies, providing an example of the powerful combination of radiopharmaceutical chemistry and cell biology.

With the recent increase in Gold (Au) wire cost Copper (Cu) wire becomes an attractive way to manage overall package cost. On the other hand, Copper wire bonding introduces much higher mechanical impact to underlying BEoL structures and actives because of the higher stiffness and lower ductility of Copper compared to Gold. These trends are accompanied by the application of new porous or nano-particle filled materials like low-k and ultra low-k materials for Back-end of Line (BEoL) layers of advanced CMOS technologies. As a result, higher delamination and cracking risks in BEoL structures underneath bonded areas represent an increasing challenge for the thermo-mechanical reliability requirements. To overcome the related reliability issues the authors performed a two level nonlinear FEM-simulation approach. Initially nonlinear axi-symmetric modeling and simulation of the copper bonding process are coupled with a spatial simulation model of the whole BeoL and bond pad structure. Cracking and delamination risks are estimated by a surface based cohesive contact approach and the utilization of a crushing foam constitutive material model for ultra low-k materials.

Bumpless interconnects and ultra-thinning of 300 mm wafers for three-dimensional (3D) stacking technology has been studied [1, 2]. In our previous studies, wafer thinning effect using device wafers less than 10 μm was investigated [3, 4]. There was no change for the retention time before and after thinning even at 4 μm in thickness of DRAM wafer [5]. In this study, the behavior of Cu contamination on an ultra-thin Si stacked structure was investigated. Thinned Si wafers were intentionally contaminated with Cu on the backside and 250 °C of heating was carried out during the adhesive bonding and de-bonding processing. An approximately 200 nm thick damaged layer was formed at the backside of the Si wafer after thinning process and Cu particle precipitates ranged at 20 nm were observed by cross-sectional transmission electron microscopy (X-TEM). With secondary ion mass spectrometry (SIMS) and EDX analyses, Cu diffusion was not detected in the Si substrate, suggesting that the damaged layer prevents Cu diffusion from the backside.

No description available.

This thesis describes the convenient routes and the preparation conditions (temperature, oxygen partial presssure) which lead to the formation of single phase materials within the quaternary system Cu-Ni-Fe-O. The investigated compositions are the solid solutions CuxNi1-xFe2O4, the ferrites occurring in the phase triangle Cu0.5Ni0.5Fe2O4 -Cu0.9Fe2.1O4 - Cu0.5Fe2.5O4 and some copper-nickel oxide solid solutions. Three synthesis routes have been used, namely (i) the preparation and the thermal decomposition of freeze-dried carboxylate precursors, (ii) the preparation and the oxidation of intermetallic phases and (iii) the preparation and the heat treatment in air of mixed oxide/metallic powders. The thermal decomposition of freeze-dried Cu-Ni-Fe formate has been found as a suitable method for preparing single spinel phases within the Cu-Ni-Fe-O system. In comparison with the conventional solid state reaction, the required temperature is much lower. Concerning the solid solution CuxNi1-xFe2O4 , a single phase spinel is formed at 1000¢XC for x < 0.7; for CuO is identified as second phase. In this latter range the formation of a pure phase required an increase of the iron content in the mixture. The other single spinel phases in the phase triangle Cu0.5Ni0.5Fe2O4 - Cu0.9Fe2.1O4 - Cu0.5Fe2.5O4 have been synthesized under special synthesis p(O2)/T-conditions. For copper ferrites Cu1-xFe2+xO4 with x ?­ 0.1, 0.2, 0.33, 0.4 and 0.5, the change in the conductivity with the temperature is irreversible. The deviation from the linearity of the conductivity ?ã as a function of the temperature occurs due to the thermal history of these samples. The saturation magnetic moment (nB) at 5K, of some synthesized CuxNi1-xFe2O4 compounds has been determined. It has been found that nB increases with the nickel content in the ferrite sample.

In dieser Arbeit wird die nanoskalige Struktur von Grenzschichten in binären metallischen Multischichten untersucht. Ausgangspunkt sind laserdeponierte Multischichten des mischbaren Systems Fe/Al und des nichtmischbaren Systems Co/Cu. Die Struktur der durch die hochenergetischen Teilchen bei der Deposition entstandenen Grenzschichten wird mit Hilfe von zahlreichen Analyseverfahren (RBS, CEMS, EXAFS, Röntgenverfahren, TEM, AES und magnetische Messungen), sowie Simulationsrechnungen auf Basis des ballistischen Mischens (TRIDYN) untersucht. Anschließend wird mit Hilfe von Ionenstrahlmischen und thermischem Anlassen die Grenzschichtstruktur weiter modifiziert.